Implements become eligible to receive Impurity via a thought dedicating them for use: Succah 13b-14a; Menachot 69a
Whether receipt of Impurity by an implement from its outside is Biblical or Rabbinic: Niddah 7b
Determination of the use of an implement is based on what it is fit for, not what it is actually used for: Shabbat 123a
Implements become Impure from contact with Water of the Red Heifer: Pesachim 17b
Implements Receiving Impurity from Food: Pesachim 18b
Implements Receiving Impurity via Liquid Biblically/Rabbinically: Pesachim 16a, 17b-18b, 19b, 20a
Implements Receiving Impurity from Liquid in the Temple: Pesachim 19b
An implement receives Impurity from a sheretz, to reach the Initial Descendant Level of Impurity: Pesachim 20a-b
An implement receiving impurity because it is inside a receptacle which also contains a sheretz: Pesachim 20a-b
If an item is considered important for the prohibition against Leaven on Pesach, that makes it count for A Separation, during Pesach, to prevent Impurity of implements: Pesachim 46a
If an item is still in a preparatory state, but is already useful: Shabbat 141b
If an item is connected to the ground: Shabbat 81a
Purification
Whether implements require physical alteration, and not a mental change of use, to remove impurity: Succah 13b-14a
The minimum size of a hole in a non-business vessel to remove the vessel from Impurity capability is that of a Pomegranate: Shabbat 112b; Eruvin 4b, 24a; Succah 5b-6a
The above, as a Law spoken to Moshe at Sinai: Eruvin 4b; Succah 5b-6a
If a hole was smaller than a Pomegranate, and then was fixed, and then another hole was made which would have combined with it to reach a Pomegranate: Shabbat 112b; Eruvin 24a
An implement losing Impurity if it is digested, while whole, by an animal: Menachot 69a
Purifying a "tanur shel achnai" - an oven comprised of joined segments: Berachot 19a; Bava Metzia 59a-b
Implements made of specific materials
If a wood Vessel is not mobile when empty or full: Shabbat 83b; Megillah 26b
If a wood Vessel is flat, without projections: Shabbat 123b
For pottery implements, there is no concern of mobility: Shabbat 83b
Size of a clay pot's hole to render the plant inside the pot "connected to the ground" beneath [depends on the pot's usage]: Shabbat 95b-96a
implements made of Feces, Stone or Earth do not receive Impurity: Shabbat 96a, Menachot 69b [and for an example of such an implement, see the Maroka on Bava Metzia 47a-b
Whether an implement constructed during digestion by an animal is considered an implement made of feces or not: Menachot 69a-b
A cloth of less than 3 square finger-breadths: Eruvin 29b-30a; Succah 16a
Considering something a garment based on popular use: Eruvin 29b-30a
A sponge: Shabbat 143a
A bed: Succah 16a
A glass vessel which was pierced, and then sealed with lead: Rosh HaShanah 19a-b
Items which are inside clay pottery along with an impure item, where the impure item is in its own sealed segment: Niddah 17a-b
Transmitting impurity from an implement to something else
Making other implements impure: Pesachim 19b
An implement with a sheretz inside it makes food impure inside it to reach the Second Descendant Level of Impurity: Shabbat 138b, Pesachim 20a-b
An implement with a sheretz inside it doesn't make implements Impure inside it: Shabbat 138b, Pesachim 20a-b
The status of an item on which a formerly impure utensil is found, when it is unclear whether the utensil or the item was capable of communicating or contracting impurity at the moment of their initial contact: Niddah 4a
Making liquids or foods impure, where the vessel received impurity from a liquid: Niddah 7b
Implements which have differentiated insides and outsides
If impure Liquids touch the outside, or the inside: Pesachim 17b; Niddah 7b
If a sheretz touches the outside, or the inside: Pesachim 17b
The difference between implements which become impure from their insides/outsides: Niddah 7b
There was no Edict of Impurity on implements of Doubtful Impurity in Jerusalem: Pesachim 19b
Implements of Doubtful Impurity from elsewhere, which were then brought into Jerusalem: Pesachim 19b
Implements in Jerusalem on the path leading towards entering the Ritual Bath: Pesachim 19b
Implements in Jerusalem in alleys lining the path which enters and exits a Ritual Bath: Pesachim 19b
Miscellaneous specific implements
A Boat at sea: Shabbat 83b-84a
A Boat which is pulled by ropes alongside a waterway: Shabbat 83b-84a
The Above Boat, connected to a Rooved Structure containing a Corpse: Shabbat 101b
3 Types of Wagons, and their levels of Impurity: Shabbat 84a
3 Types of Boxes, and their levels of Impurity: Shabbat 84a
Teeth of Keys: Shabbat 81a
A staff used to move olives in their bin: Shabbat 123b
An oven which is not merged with the ground beneath it: Shabbat 125a
Differentiating, in the line above, between an oven which has never been used and one which has: Shabbat 125a
Coins which have been converted into weights: Bava Metzia 52a
